Popular selective serotonin reuptake inhibitors (SSRIs) are associated with increased risk of bleeding, transfusion, hospital readmission and death when taken around the time of surgery, according to researchers from UC San Francisco and Baystate Medical Center in Massachusetts.

Medical records of more than 530,000 patients who underwent surgery at 375 U.S. hospitals were examined. The results were published last year in JAMA Internal Medicine.

The lead researcher noted that “SSRIs are known to interfere with the functioning of platelets – blood cells that play a crucial role in blood clotting. In turn, platelet dysfunction can lead to excess bleeding.”

While there are natural therapies for depression, many people are on SSRIs for convenience, even though potential side effects are numerous. If you or a loved one are taking SSRIs and intend to have surgery, be sure to talk to your doctor prior to any operation.